Golf balls having multi-layer cores are known. For example, U.S. Pat. No. 6,852,044 discloses golf balls having multi-layered cores having a relatively soft, low compression inner core surrounded by a relatively rigid outer core. U.S. Pat. No. 5,772,531 discloses a solid golf ball comprising a solid core having a three-layered structure composed of an inner layer, an intermediate layer, and an outer layer, and a cover for coating the solid core. U.S. Patent Application Publication No. 2006/0128904 also discloses multi-layer core golf balls. Other examples of multi-layer cores can be found, for example, in U.S. Pat. Nos. 5,743,816, 6,071,201, 6,336,872, 6,379,269, 6,394,912, 6,406,383, 6,431,998, 6,569,036, 6,605,009, 6,626,770, 6,815,521, 6,855,074, 6,913,548, 6,981,926, 6,988,962, 7,074,137, 7,153,467 and 7,255,656.
Golf balls comprising a layer having a non-uniform thickness are also known. For example, U.S. Pat. No. 9,254,422 discloses an inner core made of a foam composition and having a non-uniform structure including projecting members, and U.S. Patent Application Publication No. 2012/0184396 discloses multi-layer core golf balls including at least one thermoset core layer and at least one thermoplastic core layer, wherein one or more of the golf ball layers is optionally a non-uniform thickness layer.
The present invention provides a golf ball construction wherein a multi-layer core comprising a thermoset inner core layer, a thermoplastic intermediate core layer, and a thermoset outer core layer, and including at least one layer having a non-uniform thickness, contributes to a golf ball having unique construction and performance properties.